Key Techniques for No-Till Cultivation of Autumn Potatoes with Rice Straw Mulch

Autumn potatoes can be harvested in December and marketed as table potatoes, giving good returns. Adopting no-till planting of autumn potatoes with rice straw mulch not only saves labor and time and reduces labor intensity, but also prevents environmental pollution caused by burning rice straw, and can increase yield by more than 10% compared with plowed planting. The key cultivation points are as follows.

1. Select early-maturing, excellent varieties. The effective growth period of autumn potatoes is short, generally 80-90 days. Therefore, seed potatoes should be selected from varieties with early maturity, fast tuber enlargement, and good yield and disease resistance, such as Dongnong 303, Holland 15, etc.

2. Sow early at the right time. Generally, sowing is best when the daily average temperature is stably below 25°C. In mountainous areas at an altitude of 500-800 m, sowing in late August is appropriate; in areas below 500 m, the suitable sowing period is late August to early September.

3. Use pre-sprouting before sowing. When potatoes are sown in autumn, the temperature is still relatively high, which is unfavorable for seed potato germination. Sowing without pre-sprouting often results in late and uneven emergence. Therefore, 7-10 days before sowing, soak the seed potatoes in "920" solution to promote sprouting. For small whole seed potatoes, soak in "920" solution at a concentration of 4 mg/L for 20-30 minutes; for large potatoes, cut them into 2-4 pieces, first soak in 1% potassium permanganate solution for sterilization, take them out and drain the water, then soak in "920" solution at 1 mg/L for 5-10 minutes. After soaking, air-dry the moisture and use a sand bed for sprouting. That is, spread a 4 cm thick layer of moist fine sand on the indoor floor (moist enough to hold together when squeezed by hand and crumble when touched), then place a layer of seed potatoes and cover with 1 cm thick fine sand. After laying 3-4 layers of seed potatoes in this way, cover again with 4-6 cm thick moist fine sand and a layer of rice straw, and finally cover with plastic film to keep warm and moist. After sprouting, they can be sown.

4. Plant in narrow beds with deep furrows. When harvesting rice, first cut the rice level with the soil, then open beds and dig furrows according to a bed width of 1.6 m, furrow width of 15 cm, and furrow depth of 20 cm, and at the same time open the main furrow and surrounding furrow well, so that the three furrows are fully matched. When sowing, place the seed potatoes on the bed surface at a row spacing of 30 cm and a hill spacing of 23 cm, and make them closely contact the soil. Apply 50-60 kg of ternary compound fertilizer (45% effective ingredient content) per mu, 7-8 cm away from the seed potatoes, in bands between the rows, and cover the seed with 1500 kg of decomposed farmyard manure per mu; finally cover with 1000 kg of rice straw per mu in the direction perpendicular to the beds, so that it is uniform without letting light through or exposing soil. After sowing, if drought occurs, pay attention to irrigation for drought resistance; if autumn rain occurs, drain water to prevent waterlogging. During the growth period, apply 2-3 foliar topdressings of a mixed solution of 0.2% potassium dihydrogen phosphate and 0.5% urea.

5. Pest and disease control. Aphids and viral diseases occur more seriously in autumn potatoes, so use 10% imidacloprid (imidacloprid, Yibianjing, Dagongchen) to control aphids as early as possible, and use 5% Junduqing or 20% Virus A to control viruses.